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During the past three decades, the world has seen signifi cant changes in the telecom- munications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from fi rst-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wire- less personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs).
標簽： Communications Networking Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea phone call, or sitting in front of a personal computer to send an e-mail or download a video program, has become an old story. Nowadays it is commonplace for people to talk over a cell phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain. Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications over three generations, with the fourth generation being under way.
標簽： Communications Management Wireless Resource
上傳時間： 2020-06-01
上傳用戶：shancjb
Wireless Mesh Networks (WMN) are believed to be a highly promising technology and will play an increasingly important role in future generation wireless mobile networks. WMN is characterized by dynamic self-organization, self-configuration and self-healing to enable quick deployment, easy maintenance, low cost, high scalability and reliable services, as well as enhancing network capacity, connect- ivity and resilience.
標簽： Networking Wireless Mesh
上傳時間： 2020-06-01
上傳用戶：shancjb
This chapter provides extensive coverage of existing mobile wireless technologies. Much of the emphasis is on the highly anticipated 3G cellular networks and widely deployed wireless local area networks (LANs), as the next-generation smart phones are likely to offer at least these two types of connectivity. Other wireless technologies that either have already been commercialized or are undergoing active research and standardization are introduced as well. Because standardization plays a crucial role in developing a new technology and a market, throughout the discussion standards organizations and industry forums or consortiums of some technologies are introduced. In addition, the last section of this chapter presents a list of standards in the wireless arena.
標簽： Networking Wireless Complete
上傳時間： 2020-06-01
上傳用戶：shancjb
This book paves the path toward fourth generation (4G) mobile communica- tion by introducing mobility in heterogeneous IP networks with both third generation (3G) and wireless local area networks (WLANs), which is seen as one of the central issues in the becoming 4G of telecommunications networks and systems. This book presents a thorough overview of 3G networks and standards and discusses interworking and handover mechanisms between WLANs and the Universal Mobile Telecommunication System (UMTS).
標簽： Wireless towards WLANs WPANs 4G
上傳時間： 2020-06-01
上傳用戶：shancjb
It has been said that the move from narrowband to broadband access is the second revolution for the Internet — ‘broadband is more bandwidth than you can use’. Once users have experienced broadband access there is no turning back. A whole new world of applications and services becomes possible. No longer is it the ‘world- wide wait’. The speed of response and visual quality enabled by broadband finally allows the Internet to reach its true potential.
上傳時間： 2020-06-06
上傳用戶：shancjb
The “bottom-line” metrics of cash flow, demand, price, and return on investment are driven by a second set of financial metrics represented by value to the customer, cost, and the pace of innovation. Get them right relative to competition and impressive bottom-line results should follow. Because of their importance, we call value to the customer, variable cost, and the pace of innovation the “fundamental metrics.”
標簽： Planning Product Systems Driven Value and
上傳時間： 2020-06-06
上傳用戶：shancjb
Electricity has been chosen as the most convenient and useful form of energy, due to its ease of transportation over large distances and easy conversion to other energy forms. The biggest inconvenience with electricity is that it cannot be stored and must be utilized at the moment of generation. The storage of a large amount of electrical energy is usually connected with its conversion to other types of energy, which significantly reduces the efficiency of such processes. The aim of the power system, often treated as the biggest and the most complex machine ever built, is to deliver uninterruptible electric energy of demanded quality parameters to consumers.
標簽： Electromagnetic Interference Conducted
上傳時間： 2020-06-07
上傳用戶：shancjb
I would like to thank you for purchasing the second edition of “Industrial Network Security,” especially if you are one of the many supporters of the first edition. When the second edition was announced, many people asked me, “why a second edition?” and even more followed that up with, “and why a coauthor?” These ques- tions are harder to answer than you would think.
標簽： Industrial Security Network
上傳時間： 2020-06-07
上傳用戶：shancjb
A revolution in power industries, including generation, transmission and distribution, driven by environmental and economic considerations, is taking place all over the world. The smart grid allows for integration of diverse generation and storage options, reduced losses, improved efficiencies, increased grid flexibility, reduced power outages, allowing for competitive electricity pricing and integration of electric vehicles and overall becoming more responsive to market, consumer and societal needs. It is bringing profound changes to both power systems and many related industries.
標簽： Measurement Innovative Solutions Testing and
上傳時間： 2020-06-07
上傳用戶：shancjb
